Field
The disclosed concept relates generally to circuit interrupters and, more particularly, to circuit interrupters with associated settings and diagnostic information. The disclosed concept also relates to communication systems and associated methods, which include circuit interrupters with associated settings and diagnostic information.
Background Information
Circuit interrupters, such as for example and without limitation, circuit breakers, are typically used to protect electrical circuitry from damage due to an overcurrent condition, such as an overload condition, a short circuit, or another fault condition, such as an arc fault or a ground fault. Circuit breakers typically include separable contacts. The separable contacts may be operated either manually by way of an operator handle or automatically in response to a detected fault condition. Typically, such circuit breakers include an operating mechanism, which is designed to rapidly open the separable contacts, and a trip mechanism, such as a trip unit, which senses a number of fault conditions to trip the breaker automatically. Upon sensing a fault condition, the trip unit trips the operating mechanism to a trip state, which moves the separable contacts to their open position.
It is well known to employ trip units which utilize a microprocessor to detect various types of overcurrent trip conditions and provide various protection functions, such as, for example, a long delay trip, a short delay trip, an instantaneous trip, and/or a ground fault trip. The long delay trip function protects the load served by the protected electrical system from overloads and/or overcurrents. The short delay trip function can be used to coordinate tripping of downstream circuit breakers in a hierarchy of circuit breakers. The instantaneous trip function protects the electrical conductors to which the circuit breaker is connected from damaging overcurrent conditions, such as short circuits. As implied, the ground fault trip function protects the electrical system from faults to ground.
The earliest electronic trip unit circuit designs utilized discrete components such as transistors, resistors and capacitors. More recently, designs, such as disclosed in U.S. Pat. Nos. 4,428,022; and 5,525,985, have included microprocessors, which provide improved performance and flexibility. These digital systems sample the current waveforms periodically to generate a digital representation of the current. The microprocessor uses the samples to execute algorithms, which implement one or more current protection curves.
Electronic trip units have various settings which can be adjusted to change the behavior of the electronic trip unit. In several known types of circuit breakers, an interface panel, such as the interface panel 2 shown in FIG. 1, is used to adjust settings of the electronic trip unit. The interface panel 2 includes five rotary switches 4 which are used to adjust different settings of the electronic trip unit.
Using the interface panel 2 to change settings of the circuit breaker requires approaching the circuit breaker and physically interacting with the rotary switches 4 on the interface panel 2. However, it is not ideal for technicians to approach circuit breakers as it can place them in a dangerous situation due to the environment around the circuit breaker or the amount of power flowing through the circuit breaker.
Furthermore, the interface panel 2 does not provide any diagnostic information related to the circuit breaker. In some circuit breakers, a display is provided on the circuit breaker in order to view diagnostic information related to the circuit breaker. In some other circuit breakers, no display is provided, but an external module must be physically connected to the circuit breaker to read diagnostic information related to the circuit breaker. In either case, technicians must approach the circuit breaker to obtain the diagnostic information, thus potentially placing them in a dangerous situation.
Cost is also a concern with circuit breakers. Each component of the interface panel 2 adds to the cost of the circuit breaker. Additionally, a display or external module also add cost. It would be desirable to reduce the cost associated with the circuit breaker.
There is room for improvement in circuit interrupters, and in communication systems including circuit interrupters. There is also room for improvement in methods for communicating circuit interrupter information.